1. Field of the Invention
This invention relates to delivery systems for fluids. The invention relates to the delivery of liquids, gases, and mixtures thereof. More particularly it relates to providing fluid delivery from a central pressurized header to a delivery point through a delivery conduit that does not remain under pressure between deliveries of fluid. Most particularly the invention relates to the delivery of water at a desired temperature by mixing relatively hot and cold water from pressurized headers to provide a tempered mixture in a single delivery conduit with control of the flow at a point of delivery which is remote from the pressurized headers. The invention further relates to providing means by which operation of valving at a header is manipulated from a remote delivery point and to providing a mixing valve particularly adapted for use in a delivery system as described above.
2. Description of the Present State of the Field of the Invention
In most operations in which a fluid, particularly water, is delivered from a header to a delivery point the delivery conduit is pressurized to a means of closure at the point of delivery. There are, however, instances in which, because of safety considerations or for reasons of reduced cost of construction or maintenance, it is advantageous to provide a pressurized header at a centralized position and deliver fluid to points at a distance from the header through delivery conduits that are not continuously maintained under pressure.
It would, therefore, be advantageous to have a process and apparatus by which transfer of a fluid, particularly a hazardous fluid, from a pressurized header could be accomplished through a delivery conduit that is self draining, controlling the opening of a header valve from a point near the point of delivery thereby reducing to a minimum the time and area in which the fluid being delivered is maintained under pressure.
It would also be advantageous to have a process and apparatus by which the construction and maintenance costs of multiple unit housing or office space could be reduced by providing fluids, such as hot and cold water, in centralized, pressurized headers with withdrawal from these headers into a mixing valve for delivery of tempered water at a remote delivery point with the operation of the valve at the centralized header being controlled at the remote delivery point.
In the present invention not only are the advantages set out above accomplished, but also by the positioning of the height of the delivery point in relation to the height of the take off point at the pressurized header the delivery conduits can be maintained as empty or fluid full but unpressurized. This not only reduces the possibility of leakage damage by half by substituting one delivery conduit for two to each point of delivery, but also reduces leakage damage because the delivery conduits are not pressurized. It also allows the use of cheaper construction material in the delivery conduits which in some instances, such as allowing the substitution of plastic for copper, not only reduces the construction and replacement cost but also reduces the temptation to pilfer the delivery conduit piping. The present invention also eliminates the expense of the use of valving at the point of delivery of the water.
Operation of a fluid delivery system as described above is facilitated by providing a mixing valve that can be installed at the pressurized headers and can be controlled from a point of delivery of the mixed liquid that is remote from the valve. The efficiency of the mixing valve is further facilitated by having the closure mechanism of the valve operated by alternative power sources built into the valve.
It is, therefore, an object of this invention to provide a delivery system for fluids.
It is another object of the invention to provide a fluid delivery system in which at least one valve on a centralized, pressurized header is operated to discharge fluid through a delivery conduit to a delivery point remote from the centralized, pressured header.
It is a further object of the invention to provide a system in which a delivery conduit is not pressurized from the centralized header to the delivery point when fluid is not being transferred through the conduit. It is another object of this invention to provide a valve operable from a remote point of control.
It is yet another object of this invention to provide a control system for a header valve enabling the delivery of fluid to be controlled from the point of delivery of the fluid which is remote from the header valve.
It is yet another object of this invention to provide a valve that is operated using the force of the header pressure of the fluid within the valve body to power the opening and closing of the valve.
It is another object of this invention to provide a valve for mixing fluids. Preferably, the valve for mixing fluids is provided with alternative mechanisms by which the liquid flow to a mixing chamber in the valve can be controlled by alternatively using combinations of standard commercial electricity, reserve low voltage backup battery electricity, header pressure in a liquid transfer system and a compressed gas backup system.
Another object of the invention is to provide means for minimizing the effects of pressure differentials caused by surges in the pressure of the fluid entering the mixing valve.
These and other aspects and objects of the invention will become apparent on studying the following specification and claims along with the appended drawings.